Placental Size and Uterine Artery Doppler for Prediction of Adverse Pregnancy Outcomes in Women with Low Pregnancy-Associated Plasma Protein-A

Background: Patients with a low level of pregnancy-associated plasma protein-A (PAPP-A) experience more placental disorders in the second trimester. Objectives: We aimed to assess UtA-Doppler and placental size to predict adverse pregnancy outcomes in a woman with placental insufficiency and low PAPP-A. Methods: Following a cross-sectional design, 83 singleton pregnant women with normal chromosomes and PAPP-A ≤ 0.5 were examined at 11 - 13 + 6 weeks of gestation. All participants with PAPP-A ≤ 0.5 were tested in the Nilo laboratory of Tehran from 2018 to 2019. The placental size and Doppler uterine artery were assessed at 18 - 20 weeks. Three cases were excluded due to abortion and aneuploidy. All participants were assigned to placenta lengths of 10 cm and 10 cm. All comparisons between two groups were assayed by the independent t-test, Mann-Whitney U test, χ^2-test or Fisher exact test, and Logistic regression model. Results: Of 80 women, 48 (60%) had placenta length of 10 cm and 32(40%) had placenta length of 10 cm. Fourteen (17.5%) were preterm ( 32 weeks), and 36(45%) were IUGR. According to the logistic regression model, in participants with a placenta length of 10 cm, the risk of IUGR was higher by 9-time than those with placenta length of 10 cm (OR = 9, CI95% = 3.20 - 25.29). Also, the risk of preterm labor was 3.47 fold higher in the group with placenta length of 10 cm, OR: 3.47;( CI95% = 1.27 - 9.44). Sensitivity of placenta length of 10 cm for predicting IUGR was 75% (CI95% = 56.60 - 88.54). Conclusions: Placental length measurement in the second trimester can help predict adverse pregnancy outcomes in pregnant women with low PAPP-A. Placenta evaluation can assist in planning future pregnancy care to detect the pathology of fetal growth restriction.